Muskarinové

Muskarinové refers to substances that act as agonists at muscarinic acetylcholine receptors. These receptors are a type of G protein-coupled receptor found in the autonomic nervous system, playing a crucial role in parasympathetic nervous system function. Muscarinic agonists mimic the action of the neurotransmitter acetylcholine at these receptors.

There are five subtypes of muscarinic receptors: M1, M2, M3, M4, and M5. Each subtype is distributed differently throughout the body and mediates distinct physiological effects. For example, M1 receptors are primarily found in the central nervous system and exocrine glands, while M2 receptors are prevalent in the heart. M3 receptors are located in smooth muscle, glands, and the eye.

Muscarinic agonists can have a wide range of effects depending on which receptor subtypes they activate and their route of administration. They can cause effects such as decreased heart rate, increased smooth muscle contraction (leading to bronchoconstriction or gastrointestinal motility), increased glandular secretions (salivation, sweating), and pupil constriction.

Examples of muscarinic agonists include naturally occurring compounds like muscarine itself, a toxin found in certain mushrooms, and synthetic drugs such as pilocarpine, used to treat glaucoma and dry mouth, and bethanechol, used to treat urinary retention. These compounds are important in pharmacology due to their therapeutic applications and are also studied for their physiological roles.